The present invention relates to equipment used to monitor and control industrial processes. More specifically, the present invention relates to displays for transmitters which are used to measure process variables of an industrial process.
Industrial processes are used to monitor and control process fluids such as for manufacturing or refining. Example industrial processes include oil refineries, food manufacturing plants, paper pulp preparation facilities, and many others.
In industrial processes, it is often necessary for an operator to obtain information regarding the operation of the process. Remote units, known as “transmitters,” are coupled to the process and transmit information related to process variables (pressure, temperature, flow rate, etc.) to a control room. The process variables can be viewed or operated upon with equipment in the control room.
In some instances, it is desirable for an operator to view information from a process transmitter directly. Therefore, some process transmitters include displays which are used to directly display the measured process variable or other information related to the transmitter on a face of the transmitter. For example, an operator can use the display to calibrate or configure the process transmitter.
Although process transmitters have many physical configurations, a common design includes a housing having a process coupling side or a process couple face and a cylindrical cavity which houses various transmitter circuitry. The cylindrical housing arranged perpendicular to the process coupling face and is sealed with end caps which screw into each end of the cylinder. When a display is added to such a transmitter, it is typically located near one of the end caps. The end cap can have a clear window such that the display can be viewed externally. The display itself is typically rectangular and is placed squarely on the transmitter housing, i.e., it is oriented such that the long sides of the rectangular display are parallel to a width of the transmitter and the short sides are parallel to a height. Information is then displayed in a standard fashion across the width of the rectangular display, with the displayed characters and symbols aligned with the sides of the display.